340 CLAVICORNIA. 



three or five-jointed ; maxillae with one lobe ; elytra not 

 covering apex of abdomen ; hinder pairs of coxae placed 

 apart. Conjloj^hidae. 



b b. Labial palpi not very short. 



A a. Posterior coxae dilated. 



Antennae nine-jointed, very thin, with abrupt two- 

 jointed club ; maxillae with two lobes ; tarsi four-jointed ; 

 insects capable of rolling up into almost a perfect ball. 



Clamhidae. 

 Ti b. Posterior coxae not dilated. 



A 1» Posterior trochanters not projecting 

 from femora. 

 Club of antennae with from three to five joints, in latter 

 case its second joint small ; episterna of metathorax wholly 

 or nearly entirely covered by reflex ed margin of elytra ; 

 posterior coxae approximated ; abdomen with six ventral 

 segments ; number of tarsal joints variable. 



Anisotomidae. 

 S 1, Posterior trochanters projecting 

 from femora. 

 Antennae either gradually or abruptly clubbed ; elytra 

 often abbreviated ; episterna of metathorax not covered ; 

 abdomen with six ventral segments ; posterior coxae ap- 

 proximated ; tarsi nearly always five-jointed. Silphidae. 



2, Anterior coxae glol)ular or cylindrical. 



A A. Antennae elbowed. 



Antennae with first joint very long, club compact, three- 

 jointed ; mandibles very strong ; abdomen with five ventral 

 segments ; anterior coxae cylindrical, enclosed, posterior 

 coxae placed ajjart ; legs broad and flat, tarsi five-jointed, 

 short ; body without pubescence ; elytra almost always 

 abbreviated, leaving last two segments of abdomen un- 

 covered, apex truncate, each normally bearing the following 

 striae, viz : a sutural stria, five dorsal striae (numbered 

 from toward suture), an oblique stria on shoulder (humeral 

 stria), an inner lateral stria, placed nearer apex than 

 humeral stria and sometimes attached to latter, and an 

 outer lateral stria, placed at base, outward from humeral 

 stria ; all these striae are in various cases absent or abbre- 

 viated ; the reflexed margin of elytra also sometimes bears 

 one or two striae. Histeridae. 



